Drafting board



Jan. 21, 1947. H. E. PAGE 2,414,606

DRAFTING BOARD Filed Feb. 16, 1945 I I! ii f- 'IIIIIIIIIIIIII. E J'IIIII'IIIIIIIIJ IlIlllIllIlIIll/a; 'IIIIIIIIIIII'I :Henber t E... l a 5 c slat/ IN VEN TOR.

Patented Jan. 21, 1947 UNITED STATES PATENT OFFICE DRAFTIN G BOARD Herbert E. Page, Alhambra, Calif.

Application February 16, 1945, Serial No. 578,339

8 Claims. 1

My present invention has to do with drawing board devices, having as an object the provision of a drafting board embodying novel means for rotatively adjusting the drawing to any desired angle without any danger of smearing or blotting the drawing.

Another object is the provision of a novel drafting board embodying vacuum means for retaining the drawing sheet in flat conforming engagement against the drawing board surface.

Another object is the provision in such a device of means for releasably retaining the drawing board in any desired position of adjustment.

Still further objects and advantages of a more specific nature will appear from the following detailed description of a presently preferred embodiment of the invention, although within the scope of the broader claims appended hereto it will be understood that the invention is susceptible of bein embodied in other and modified physical forms which the followin explanation will suggest to those working in this art.

For purposes of the following description I shall refer to the accompanying drawing, in which:

Fig. 1 is a top plan view;

Fig. 2 is a section on line 2-2 of Fig. 1;

Fig, 3 is a section taken on line 3-3 of Fig, l; and

Fig. 4 is a side elevation taken as indicated by the line 44 of Fig. 1.

Referring now to the drawing, I show at 5 a base providing a round cavity 8 within which is rotatably mounted a, round body 8 presentin a rectangular vacuum chamber 9 covered by a drawing board l having a plurality of small perforations II. The board I0 is secured on the body 8 by screws l and a sealing gasket I6 is interposed between the body and board to provide an airtight seal therebetween. Board Ill is rotatably secured to the base by a pivot pin l1 having a longitudinal air passageway Hi, the pin having a nut l9 threaded onto its lower end.

The base has a bore or cylinder within which is reciprocably mounted a plunger 2| which has a connecting rod 22 terminating at its outer end in a ring 23 for manual manipulation, the plunger being normally urged inwardly of the cylinder by a coil spring 24. The plunger is of the cup washer type so that as it is moved inwardly air may pass around its periphery.

Also provided in the base there is a chamber whose outer end is closed by a threaded plug 3| having an air port 32, and within which chamber is mounted a plunger urged outwardly by a coil spring 36.

Cylinder 20 communicates with chamber 9 through port 40 in the base and axial opening l8 in pin l1; opening l8 communicating at one end with port 40 and at its other end with chamber 9. Chamber 9 also communicates through opening l8 and ports 4| and 42 with chamber 30. A check valve 45, urged against its seat by a leaf spring 48. controls port 40, seating towards chamber 9.

To either lock the body 8 against rotation relative to the base, or to brake its rotative movement, or to allow it to be freely rotatable, I provide a lever pivotally mounted on the base by a pin 5| in a recess 52 in the base, the lever having pivotally connected to its outer or left-hand end, by a pin 53, a trigger 54. The trigger prcsents a shoulder 55 which may be engaged under the projection 56 provided by the base. A spring 51, secured at one end to the lever and at its other end to the trigger, urges the trigger against the stop 58 carried by the base. The left-hand end of the lever 50 is urged upwardly by a spring 60 to resiliently urge the right-hand end of the lever into engagement with the periphery of the body 8. The spring 60 also acts to yieldably retain the shoulder 55 against the projection 56 when it is desired to lock the device in such position that the body 8 is free to rotate.

The function and cooperation of the described parts will be understood from the following explanation of operation of the device:

First, a drawing sheet, which may, be, for instance, a sheet of Bristol board B, is laid flatly against the top surface of board In inposition covering the perforations I I. If desired, the corners of the sheet B may be secured to the board by means of the usual adhesive strips S. To draw the sheet B smoothly against the surface of the board and to retain it in such position, the plunger 2| is manually manipulated to create a vacuum in chamber 9. Inasmuch as the chamber 9 is also in communication with chamber 30, the vacuum in chamber 9 may be furthermore positively maintained by the plunger 35, since as the air is exhausted from chamber 9, the plunger 35 will be drawn inwardly against spring 35 and the spring 36 will urge the plunger 35 outwardly to maintain the vacuum in chamber 9. Plunger 35 may be used to create the vacuum independently of piston 2| if desired. and for this purpose I provide plunger 35 with a rod 35a which projects outwardly through plug 3|, so that the plunger may be manually pushed inwardly against the spring, air in the cylinder 30 passing out around the plunger during such inward movement, and then released to allow the spring to move the plunger in the opposite direction to draw the vacuum.

By moving the trigger 54 to the left until its shoulder 55 engages under the projection 56, the lever 50 will free the body 8 so that the latter may be rotated to any desired position of angular adjustment of the board In, which position may be visually observed by registration of indicia l onthe board Ill with the marker H on the base.

Transversely on the base and body I slidably mount a parallel ruler I which has depending end portions 16 slidably engaging the sides of the base. The base is Slightly higher than the top surface of the board I ll so that the ruler l5 is"always slightly spaced from the drawing.

To remove the drawing sheet B, the adhesive strips S are removed and by manually lifting a corner of the sheet S until one or more of the perforations II is uncovered, the chamber 9 will be placed in communication with atmosphere through the perforations to release the vacuum in chamber 9.

I claim:

1. A device for supporting drawings, comprising a base, a body mounted on the base to rotate about an axis perpendicular thereto, said body having a fiat drawing sheet retaining portion, a vacuum chamber in the body beneath the drawing sheet retaining portion, perforations through said last-named portion communicating with the vacuum chamber, said drawing sheet retaining portion being adapted to receive a drawing sheet in covering relationship to the perforations, and means in the base communicating with the chamber for creating a vacuum in said chamber.

2. A device for supporting drawings, comprising a base, a body mounted on the base to rotate about an axis perpendicular thereto, said body having a fiat drawing sheet retaining portion, a-

vacuum chamber in the body beneath the drawing sheet retaining portion, perforations through said last-named portion communicating with the vacuum chamber, said drawing sheet retaining portion being adapted to receive a drawing sheet in covering relationship to the perforations, and means for creating a vacuum in said chamber, including a cylinder in the base, conduit means providing communication between the chamber and cylinder, a piston in the cylinder and check valve means in the conduit means seating towards the chamber.

3. A device for supporting drawings, comprising a base, a body mounted on the base to rotate about an axis perpendicular thereto, said body having a flat drawing sheet retaining portion, a vacuum chamber in the body beneath the drawing sheet retaining portion, perforations through said last-named portion communicating with the vacuum chamber, said drawing sheet retaining portion being adapted to receive a drawing sheet in covering relationship to the perforations, and means for creating a, vacuum in said chamber, including a cylinder in the base, conduit means providing communication between the chamber and cylinder, a piston in the cylinder, a spring bearing against the piston to urge the latter in a direction away from the conduit means whereby to exhaust air from the conduit means and chamber, and means for moving the piston in the opposite direction.

4. A device for supporting drawings, comprising a base, a body mounted on the base to rotate about an axis perpendicular thereto, said body having a flat drawing sheet retaining portion, a

vacuum chamber in the body beneath the drawing sheet retaining portion, perforations through said last-named portion communicating with the vacuum chamber, said drawing sheet retaining portion being adapted to receive a drawing sheet in covering relationship to the perforations, and means for creating a vacuum in said chamber. including a cylinder in the base, conduit means providing communication between the chamber and cylinder, a piston in the cylinder for exhausting air from the chamber, and means for maintaining said vacuum, including a second cylinder in the base, a conduit providing communication between the latter cylinder and the chamber, a plunger in the latter cylinder and a spring member urging the plunger outwardly of the latter cylinder away from the chamber and the latter conduit, said plunger being movable inwardly of the latter cylinder against pressure of the spring in response to vacuum in the chamber.

5. A device for supporting drawings, comprising a base, a body mounted on the base to rotate about an axis perpendicular thereto, said body having a fiat drawing sheet retaining portion, a vacuum chamber in the body beneath the drawing sheet retaining portion, perforations through said last-named portion communicating with the vacuum chamber, said drawing sheet retaining portion being adapted to receive a drawing sheet in covering relationship to the perforations, means in the base communicating with the chamber for creating a vacuum in said chamber, and locking means cooperating with the base and body to lock the body against rotative movement relative to the base.

6. A device for supporting drawings, comprising a fiat-topped base having an upwardly opening round cavity, a round drawing board member mounted in and coaxial with the cavity, said board having a flat top surface, pivot pin means securing the drawing board member to the base for rotation relative thereto, said pivot pin having an axial bore, a vacuum chamber in the drawing board member, said member being adapted to receive a drawing sheet disposed flatly against its top surface and having perforations extending from said surface into communication with the chamber, and means in the base for creating a vacuum in said chamber, said last-named means communicating with the chamber through the bore in said pivot pin.

7. A device for supporting drawings, comprising a fiat-topped base having an upwardly opening round cavity, a round drawing board member mounted in and coaxial with the cavity, said board having a flat top surface, means pivotally securing the drawing board member to the base for rotation relative thereto, and means for releasably locking the drawing board member against rotation relative to the base, including a lever pivotally carried by the base for engagement at one end against the periphery of the drawing board member, spring means bearing against the other end of the lever to urge the lever into locking position, and trigger means for moving the lever against the action of the spring to disengage the lever from the drawing board member.

8. A device for supporting drawings, comprising a flat-topped base having an upwardly opening round cavity, a round drawing board member mounted in and coaxial with the cavity, said board having a flat top surface, means pivotally securing the drawing board member to the base for rotation relative thereto, means for releasably locking the drawing board member against rotation relative to the base, including a lever pivotally carried by the base for engagement at one end against the periphery of the drawing board member, spring means bearing against the other end of the lever to urge the lever into looking position, trigger means for moving the lever against the action of the spring to disengage the lever from the drawing board member, and means for locking the trigger means when the lever is 5' in the last-named position.

HERBERT E. PAGE. 

